Farmers are being reminded to keep a close eye on their canola crops as some growers are reporting their seed has failed to properly germinate.

Despite a near perfect start to the season, some Great Southern farmers have noticed very poor emergence with their roundup ready hybrid canola, with some plants appearing deformed and others emerging very weakly and prone to insect attack.

Rural Reporter Owen Grieve has spoken to farmers in the Borden and Green Range areas who've reported poor emergence of canola but he understands it's more widespread.

He knows of three farmers at this stage who've had to re-seed their canola paddocks.

ABC understands the seed company or companies involved are investigating the problem.

There is no certainty that it's the seed at fault here when there are many other variables involved from the time farmers buy the seed to planting and then crop emergence.

Mr Grieve says this is the biggest unknown.

"That's the question the companies who've provided the package need to find out."

"Is it the plant, is it the genetics, is it the fertiliser - all sorts of things need to be opened up and looked at."

If you've just seeded canola or haven't inspected your canola crops for a while it's suggested you do so immediately and look for signs of poor germination or any crop deformity.